1. Field of the Invention
The present invention relates to a release switch apparatus in which the operational states of a shutter button of a camera can be visually confirmed, and to a release switch apparatus in which a reaction force to the operation of the shutter button can easily be optimized.
2. Description of the Related Art
The release switch of a camera is usually of a two-step type in which a shutter button (release button) is pushed down by a half step for a first operation and by a full step for a second operation, respectively. Specifically, when the shutter button is pushed down by a half step, the photometering mechanism, the automatic focusing mechanism, and so on are actuated, and when it is pushed down by a full step, a shutter release (exposure) device is actuated. To this end, the conventional shutter button has an association member which detects and commences the first and second operations. The association member, which is, for example, in the form of a lever for a mechanical shutter or in the form of a contact switch for an electromagnetic shutter, operates in association with the operation of the shutter button.
A photographer receives (i.e., feels) different reaction forces when operating the release button, depending on whether the half step operation or the full step operation is being employed. The photographer recognizes the half step operation from the reaction thereto.
However, when a picture is taken in cold weather, for example, during outdoor photographing in extremely cold regions, or when photographing at a ski resort in winter, the photographers' fingers are often too numb to feel the reaction or, in cases where the photographer is wearing gloves, he or she is unable to feel the reaction. In addition, in cases where the camera is attached to a tripod or when a photographer actuates the shutter button while looking away from the finder, the photographer has difficulty in feeling the reaction.
To ensure that the photographer feels the reaction to the half step operation, it is possible to increase the reaction force of the association member. However, this tends to cause camera shake, particularly in a light camera. Specifically, when the release button is pushed down by a full step, the photographer tends to push the release button down until the push button reaches a lower movement limit, thus resulting in camera shake to a light camera.
To prevent camera shake, it is necessary to reduce the reaction force to the operation of the shutter button and the reaction force to the operation of the association member. However, it is very difficult for a photographer to feel a reduced reaction force. To optimize the reaction force, it is necessary to adjust the operational forces of various mechanisms which operate in association with the operation of the association member, but this is not technically practicable.
Furthermore, in a conventional camera, it is impossible for the subject being photographed to know when the shutter button is being pushed by a half step or by a full step. In particular, with the use of compact cameras, the subject being taken (i.e., photographed) has difficulty in recognizing the completion of the exposure because the sound made by the release operation is very small.